The Outcome of BNT162b2, ChAdOx1-Sand mRNA-1273 Vaccines and Two Boosters: A Prospective Longitudinal Real-World Study

Abstract

To date, the effectiveness of COVID-19 vaccines and booster doses has yet to be evaluated in longitudinal head-to-head studies. This single-center longitudinal study assessed the effectiveness of ChAdOx1 nCoV-19, BNT162b2, and mRNA-1273 vaccines and assessed two BNT162b2 boosters in 1550 participants, of whom 26% had comorbidities. In addition, the SARS-CoV-2 antibody dynamics was monitored. A group of 1500 unvaccinated subjects was included as the controls. The study’s endpoint was the development of virologically-proven COVID-19 cases after vaccine completion, while the secondary endpoint was hospitalizations due to severe COVID-19. Overall, 23 (4.6%), 16 (3%), and 18 (3.8%) participants vaccinated with ChAdOx1 nCoV-19, BNT162b2, and mRNA-1273, respectively, developed COVID-19 after vaccine completion, with an effectiveness of 89%, 92%, and 90%. Ten COVID-19 cases were reported in participants with comorbidities, three of whom were hospitalized. No hospitalizations occurred after boosters. SARS-CoV-2 antibody levels peaked 2–4 weeks after the second vaccine dose but declined after a mean of 28.50 ± 3.48 weeks. Booster doses significantly enhanced antibody responses. Antibody titers ≤ 154 U/mL were associated with a higher risk of COVID-19 emergence. Thus, COVID-19 vaccines effectively reduced COVID-19 and prevented severe disease. The vaccine-induced SARS-CoV-2 antibody responses declined after 28–32 weeks. Booster doses induced significant maintained responses. SARS-CoV-2 antibody levels may help determine the timing and need for vaccine booster doses.

What makes SARS‐CoV‐2 unique? Focusing on the spike protein

“…Tfh cells are essential for B‐cell maturation, neutralizing antibody production, and long‐term humoral immunity establishment (Meckiff et al, 2020; Rydyznski Moderbacher et al, 2020). CD8 + T‐cell immunity significantly contributes to the protective efficacy of SARS‐CoV‐2 vaccines (Kamal et al, 2023; McCallum et al, 2021a; Shen et al, 2021a; G.‐L. Wang et al, 2021).…”

“…Tfh cells are essential for B-cell maturation, neutralizing antibody production, and long-term humoral immunity establishment(Meckiff et al, 2020;Rydyznski Moderbacher et al, 2020). CD8+ Tcell immunity significantly contributes to the protective efficacy of SARS-CoV-2 vaccines(Kamal et al, 2023;McCallum et al, 2021a;Shen et al, 2021a;G.-L. Wang et al, 2021) Yorsaeng et al (2022a). indicated that CD8+ T cells are important effector cells that are expanded during an early protection window after prime vaccination.…”